June 30, 2007 6:18

Questions and Answers about the Big Bang

An intellectually curious reader named Betsy Livingstone asks:

Here is what I have always wondered & people just look at me funny when I ask it: If space was small at the beginning, & has expanded into hugeness, then how is it that we can see the beginnings by looking out in all directions? I understand that we are looking back in time, but it seems to me that it should all get somehow closer together as we look back. But of course if it got smaller, it would have to be in a certain direction, which makes no sense at all. Can you explain this paradox? A related question that came up as I read the article was this: if we are looking back in time at young galaxies, wouldn't we be seeing multiple images of the same objects at different points in time? Or are we?

OK, I actually prefer easy questions, so I'll answer the second one first. No, we aren't. Think about a very distant galaxy: just like any galaxy it's spewing out light all the time. That light flies off in all directions, including toward us, and keeps streaming past (because there's more coming all the time). But at any given time, we're seeing the light that began its journey at a specific time in the past—say, 5 billion years ago. A year from now, we'll see the light that left that galaxy a year later (more or less—I'm ignoring the fact that the galaxy is also moving away from us, which complicates things, but the idea is the same). So at any moment, we're only seeing one image of each galaxy.

The second question is harder, but it's a good one. Yes, as we look back we look toward a time when the universe was smaller. But people confuse "the universe" with "the part of the universe we can see." The actual universe is much bigger, and may even be infinite in extent. So as time goes on, light from parts that we couldn't see before come into our view. The light we now see comes from the beginning in a place that was invisible to us a billion years ago. So we see more and more of the "beginning" all the time. And since the Big Bang happened everywhere at once, we see that earliest light from all directions.

Whew. If you want more answers, just ask. Or even better, go to Ned Wright's Cosmology Tutorial, where you can hear them from an actual cosmologist. He even does it in Italian and French, the showoff.

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June 25, 2007 8:24

And Yet More on the Origin of Life

Jim Hill writes:

The interesting thing is, if you are correct with your assessment, that we get into a "catch 22" situation. Let's say you in fact make the strongly worded allegation that chemical evolution definitely occurred in a process that very likely took a very long time. If research, as expected, continues to turn up nothing for the foreseeable future, then your allegation becomes a matter of BELIEF or FAITH, because you have no data to back up your allegation. I could allege just as easily that God created life at some point, which becomes my BELIEF and FAITH. Because you have no data to contradict me, we have a real standoff.

Your allegation becomes essentially unverifiable and unknowable from a scientific point of view, which leaves us nowhere scientifically speaking.

I believe this standoff is the current state of affairs in the question of the origin of life. I look forward to your response.

Here it is: I didn't say the origin of life required millions of years; I said that's one of the things we don't know, along with our uncertainty about the chemical makeup of the Earth's surface at the time. But we're learning more about planet formation all the time. And just as we're able to speed up reactions in the laboratory once we know what they are, we may be able to do the same with a recreation of Earth's early atmosphere. All of these things are unclear as yet, but I, for one, am not prepared to say "we'll never know, God's as good an explanation as any." That's a choice you could have made in any branch of science any time in the last 2000 years, and there's all sorts of stuff we'd never have figured out. Yes, the default assumption in science is that we'll keep trying rather than throw up our hands and drop to our knees. But for my money, it's a pretty good one.

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June 24, 2007 12:46

Question from a Reader

N.B. asks

Michael, was that you who removed a paragraph from "Origin of Life" article in Wikipedia?

Nope. But as I noted earlier, any comment suggesting that if life arose naturally it should be easy to reproduce in the lab is nuts, and needed removal.

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June 22, 2007 2:38

Further on the Origin of Life

Jim Hill writes:

Wikipedia is reasonably authoritative and easy to use. Does anyone really question what it says on the matter of the origin of life? It is interesting to note that someone anonymous went into the article on "Origin of Life" on June 21, and took out a whole paragraph stating that if chemical evolution had taken place (creating the first life forms), it ought to be easy to duplicate now in the laboratory -- a point that seems logical enough to me.

Does it really? Not to me. In order to duplicate the origin of life easily in the laboratory, we'd first of all have to know the precise conditions under which it happened—which we don't at all. Even if we did, we'd also have have to know that it happened very quickly. We've only had modern laboratories for a few decades. If it took a million years, say, for a soup of chemicals to find the right arrangement to take the leap from nonlife to life, why in the world would you think it would be easy to do in a week, or a month, or a century in the lab? It takes some radioactive elements thousands of years to decay. Do you really think we could make them do it faster in a laboratory?

I can't see any basis for your logic, and if this statement appeared in Wikipedia until someone had the good sense to remove it, then I agree with you that the website is only "reasonably" authoritative. Meaning that it's sometimes absurdly wrong.

Jim further writes:

I will agree that, strictly speaking, biological evolution doesn't address the origin of life. It assumes that life already exists somehow. I also think, however, that that the difference between the studies of the origin of life and biological evolution is a fine line that many of the most ardent proponents of evolution cross over. They believe and allege that somehow non-living chemicals combined without any supernatural intervention to create the first life forms.

A fair point. But the way many anti-evolutionists use the term suggests they don't understand the fact that there's a line at all. They lump the origin of life and even the origin of the universe under the heading "evolution," suggesting serious cluelessness. Clearly, you're not among them.

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June 21, 2007 5:21

A Telescope That Sloshes

Astronomers salivate at the idea of a giant telescope on the far side of the moon--or better yet, on the floor permanently shadowed crater. There's essentially no atmosphere, so it would be as sharp as the Hubble—but without the need to launch it, you could build it with a much bigger mirror, to gather as much faint sunlight as possible.

The big problem: how do you get tons and tons of perfectly shaped glass all the way to the Moon and assemble it into a mirror without damage?

Ermanno Borra, of the University of Laval, in Quebec, has the answer, just reported in Nature: transport the mirror in a vat and pour it out when you get there. Borra has been working for decades on the idea of liquid telescope mirrors—essentially shallow, round vessels filled with a reflective liquid. Spin the vessel, and the surface of the liquid assumes a parabolic curve, deep in the center and high at the edges. That happens to be the perfect shape for concentrating light. In fact, one of Borra's co-authors, Roger Angel, of the University of Arizona Mirror Lab, has been casting the world's biggest single-slab glass mirrors here on Earth by spinning molten glass to assume the right curve, then keeping it spinning as it cools.

Borra's original idea was to use mercury—liquid at normal temperatures and highly reflective. But using it on Earth would be dangerous, because the stuff is toxic. And getting it to the moon would be very costly, because mercury is extremely dense. The new paper reports on a different technique, using (says a NASA press release) "a liquid made of 'ionic salts' that remains fluid at very low temperatures. The scientists deposited a fine layer of chromium particles on the liquidand then added a layer of silver particles." It's not as reflective yet as it needs to be, but Borra and his colleagues think they can fix that.

There's one obvious problem with the design: even in the Moon's low gravity, you can't tilt the telescope to aim at different objects, because it would spill. But that's hardly fatal: the Arecibo radio telescope, in Puerto Rico, is set in a natural geological bowl, and always points straight up too. But when objects rotate into view as the Earth turns, it sees them with extraordinary sensitivity. The same will go for Borra's telescope on the Moon...if it ever gets built.

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June 6, 2007 7:51

Stem Cell Breakthrough. Or Not.

My colleague Alice Park reports today on the new breakthrough that allows adult cells to be reprogrammed so they revert to the same pristine state as embryonic stem cells, poised to turn into any type of body tissue at all.

She explains the science thoroughly, so what's left for me to ask is: How long do you figure it will take for opponents of embryonic stem-cell research to claim this makes that ethically controversial area of science irrelevant? Forty-five seconds, tops.

It's a well-worn path down the road of spin. And it's blatant nonsense. IF this technique can be adapted to humans from mice (not yet known) and IF the potential dangers can be overcome (not yet known) and IF these cells are truly equivalent to embryonic stem cells (not yet known), THEN there might be something to the statement. As of now, it's absurdly premature--but all of that will disappear, I guarantee, in the hands of the opponents.

Which doesn't for a second mean that proponents of embryonic stem-cell research are all innocence and purity either. Anyone remember Ron Reagan's speech at the 2004 Democratic National Convention? The picture he painted of the wonders of stem-cell-based cures for Parkinson's, diabetes and many other illnesses was equally missing all the IF steps that have to be taken before it happens.

The bottom line is that stem cells might someday cure all sorts of diseases, or they might not. Embryonic stem cells might be required, or they might not. Until we do the research to answer these questions, nobody has a clue--and anyone on either side who pretends otherwise is trying to mislead you.

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June 6, 2007 10:47

Two Common Misconception About Evolution

Reader Jim Hill posted this as part of a larger comment yesterday:

Your arrogance and absolute certainty in what you believe are, to me, pretty breath-taking. You completely reject all the senator has to say, but don't address the fundamental issue he addressed -- the origin of life. Did life "evolve" from non-living chemicals or was life created by a higher power? This is an important question many wrestle with, me included, and evolution hasn't even come close to explaining how life came to be. Read what wikipedia has to say on the subject -- the origin of life."

I read it; Wikipedia rightly points out that we don't have a convincing scientific explanation yet. This doesn't especially significant, since we don't fully understand conditions at that time and certainly have no fossil record of such an event. It also suggests finding is limited because there's no practical appliation. This is nonsense. Astrobiology, of which origin-of-life studies are part, gets quite a bit of funding. Not as much as its practitioners would like, but this has little to do with "practical value." The Space Station has no practical value, and everyone knows it. We throw billions at it every year. Giant telescopes have no practical value, but get huge funding. Wikipedia is great, except when it's wrong.

But on to the misconceptions: First, evolution says nothing whatever about the origin of life; it talks about how species arise. Darwin did comment on it once, in an speculative aside, but not as a part of the theory. Many proponents of 'intelligent design" mix the two up--deliberately, I suspect.

The second misconception, which Mr. Hill also fell prey to in his comment is that a naturalistic view of evolution somehow implies the non-existence of God. It doesn't. All it says is that God's direct intervention is not required to explain the origin of species. Maybe God did intervene--but if so, he did it in such a way that his intervention is completely undetectable. Despite the highly dubious claims of ID proponents.

Speaking of which, for links to a long list of devastating critiques of Michael Behe's latest book on ID, check out ScienceBlogs.

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June 1, 2007 9:04

Why Senator Brownback Doesn't Understand Science

Senator Sam Brownback attempted to explain in this New York Times Op-Ed yesterday what he meant in the first Republican presidential debate when he raised his hand to say he didn't believe in evolution.

What he ended up doing was demonstrating that he doesn't really know much about science. If, writes the senator, "evolution means assenting to an exclusively materialistic, deterministic vision of the world that holds no place for a guiding intelligence then I reject it."

How curious. Does this mean that the senator also rejects the laws of gravity? Last I heard, they reflected that same view of the world. No scientist I've ever run into, nor even any senator, thinks that things fall to earth or planets orbit stars because God is there shoving on them. Yet many scientists do believe in God; they just don't think he has to meddle with the physical universe to make things turn out right.

Brownback goes on to say "Man was not an accident and reflects an image and likeness unique in the created order. Those aspects of evolutionary theory compatible with this truth are a welcome addition to human knowledge. Aspects of these theories that undermine this truth, however, should be firmly rejected as an atheistic theology posing as science."

Which is pretty much nonsense. The discovery that God's direct intervention isn't necessary to explain some particular aspect of the natural world doesn't in any way suggest God's non-existence (look up "atheistic" in the dictionary, Senator). Except to those whose faith is pretty weak.

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